The housing of hard disk drives for use in computer systems typically include a cover and a base plate attached with screws. Base plates support the hard disk drive assembly (e.g., spindle, motor, actuator).
One conventional base plate manufacturing process includes press working a sheet of metal with side frames mounted on opposing sides. In this process, a base plate is press worked to form a concave portion with a few holes for motor mounting. Two side frames are press worked from sheet metal and are fixedly mounted on the opposite sides of the base plate.
There are several disadvantages to this conventional process. For example, fixing the two side frames to the base plate is an additional assembly step that increases the cost of manufacturing. The side frames must be strictly controlled in the mounting position and the mounting strength. Another disadvantage is that relief surfaces for elements such as the disk, the actuator, the voice coil motor, the filter, and bosses or semi-pierces are not part of this process. Instead, all relief surfaces are generally formed as part of a machining operation. Additionally, oil and other residue that are used during the cold working operation must be removed by washing the finished base plate.